Air ventilation structure for D.C. brushless air fans

ABSTRACT

An air ventilation structure for D.C. brushless air fans provides a selected number of side apertures on the side wall of the air fan casing and slot openings at the front end of the air fan rotor. Through the side apertures and slot openings, high temperature generated during the air fan operation will be carried away and air ventilation in the air fan will increase thereby increase the air fan durability.

BACKGROUND OF THE INVENTION

[0001] This invention relates to an air ventilation structure for D.C.brushless air fans and particularly an air fan that has a elected numberof side apertures formed on the side wall of the air fan casing and slotopenings located at the front end of the rotor for carrying away hightemperature generated during air fan operation and increasing airventilation and enhancing air fan durability.

[0002] With increasing popularity of personal computers and rapiddevelopment in the computer industry, heat generation and dissipationproblem incurred to various kinds of electronic elements has become acritical and important issue. Hence using D.C. brushless air fan as themain heat dissipating element is a prevailing trend and has been widelyadapted in the computer industry. It has a simple structure and smallsize, and can rapidly resolve the heat generation and dissipationproblem incurred to electronic elements.

[0003] However while the D.C. brushless air fans now available on themarket may fix the heat dissipation problem for electronic elements,they cannot overcome the heat dissipation problem happened tothemselves. For instance, the area between the stator and rotor isclosed. It is difficult to disperse the high temperature generated inthe ferrite coils of the stator. This accumulated heat energy couldresult in excess high temperature of the air fan and dry the lubricatingoil in the bearing, and consequently cause poor lubrication effect ofthe bearing and dropping of air fan rotation speed. In the severesituations, it could even cause the air fan stop rotating or burn out ofthe ferrite coils on the stator.

[0004] There is still no effective way being found thus far to resolvethe problems of D.C. brushless air fan regard to overcome its own heatdissipation, short durability and unstable function.

SUMMARY OF THE INVENTION

[0005] The primary object of this invention is to resolve the foregoingdisadvantages. This structure according to this invention is to form aselected number of side apertures on the side wall of the air fan casingand slot openings at the front end of the air fan rotor. By means ofthis simple structure, it can carry away high temperature generatedduring air fan operation and increase air ventilation and significantlyenhance air fan durability.

[0006] The foregoing, as well as additional objects, features andadvantages of this invention will be more readily apparent from thefollowing detailed description, which proceeds with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is an exploded view of this invention.

[0008]FIG. 2 is a sectional view of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0009] Referring to FIGS. 1 and 2, this invention mainly consists of acasing 1, a stator 2, a rotor 3 and a circuit board 4 (PC board). Thecasing 1 and stator 2 are fixedly fastened together. The circuit board(PC board) 4 is fixedly disposed on the casing 1. The rotor 3 is coupledbetween the stator 2 and casing 1.

[0010] On the side wall of the casing 1, a selected number of sideapertures 11 are formed thereon. The side apertures 11 are opened in theradial direction. The front end of the rotor 3 against the air flowdirection has a selected number of slot openings 31 formed thereon. Theslot openings 31 are opened in the axial direction.

[0011] When in use, the rotor 3 rotates upon receiving electricity andbeing energized, the blades of the rotor 3 generate air ventilationbetween the rotor 3 and casing 1. Because of the slot openings 31 at thefront end of the rotor 3 and the side apertures 11 on the side wall ofthe casing 1, the high temperature generated in the stator 2 will becarried away through the side apertures 11 and slot openings 31. Hencethe temperature of the ferrite coils of the stator 2 will become lower,and air ventilation of the air fan will also increase.

[0012] Hence this invention offers a simple but effective constructionwhich can carry the high temperature generated during air fan operation,increase air ventilation and enhance air fan durability.

[0013] The air ventilation structure for D.C. brushless air fans of thisinvention mainly provides a selected number of side apertures on theside wall of the air fan casing and slot openings at the front end ofthe air fan rotor. By means of such a construction, the problems anddisadvantages happened to the conventional air fans will be resolvedcompletely.

[0014] While the preferred embodiment of this invention has been setforth for purpose of disclosure, modifications of the disclosedembodiments of the invention as well as other embodiment thereof mayoccur to those skilled in the art. Accordingly, the appended claims areintended to cover all embodiments which do not depart from the spiritand scope of this invention.

What is claimed is:
 1. An air ventilation structure for a D.C. brushlessair fan, comprising: a casing having a side wall which has a selectednumber of side apertures formed thereon; a stator fixedly fastened tothe casing; a circuit board fixedly located on the casing; and a rotorcoupled between the stator and the casing having a selected number ofslot openings formed at a front end thereof; wherein through the sideapertures and slot openings, high temperature generated during the airfan operation will be carried away and air ventilation in the air fanwill increase thereby increase the air fan durability.
 2. The airventilation structure of claim 1, wherein the side apertures are openedin a radial direction.
 3. The air ventilation structure of claim 1,wherein the slot openings are opened in an axial direction.